/*
** $Id: lbaselib.c,v 1.276 2013/02/21 13:44:53 roberto Exp $
** Basic library
** See Copyright Notice in lua.h
*/



#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define lbaselib_c
#define LUA_LIB

#include "lua.h"

#include "lauxlib.h"
#include "lualib.h"


static int luaB_print (lua_State *L) {
	int n = lua_gettop(L);  /* number of arguments */
	int i;
	lua_getglobal(L, "tostring");
	for (i=1; i<=n; i++) {
		const char *s;
		size_t l;
		lua_pushvalue(L, -1);  /* function to be called */
		lua_pushvalue(L, i);   /* value to print */
		lua_call(L, 1, 1);
		s = lua_tolstring(L, -1, &l);  /* get result */
		if (s == NULL)
			return luaL_error(L,
			LUA_QL("tostring") " must return a string to " LUA_QL("print"));
		if (i>1) luai_writestring("\t", 1);
		luai_writestring(s, l);
		lua_pop(L, 1);  /* pop result */
	}
	luai_writeline();
	return 0;
}


#define SPACECHARS	" \f\n\r\t\v"

static int luaB_tonumber (lua_State *L) {
	if (lua_isnoneornil(L, 2)) {  /* standard conversion */
		int isnum;
		lua_Number n = lua_tonumberx(L, 1, &isnum);
		if (isnum) {
			lua_pushnumber(L, n);
			return 1;
		}  /* else not a number; must be something */
		luaL_checkany(L, 1);
	}
	else {
		size_t l;
		const char *s = luaL_checklstring(L, 1, &l);
		const char *e = s + l;  /* end point for 's' */
		int base = luaL_checkint(L, 2);
		int neg = 0;
		luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
		s += strspn(s, SPACECHARS);  /* skip initial spaces */
		if (*s == '-') { s++; neg = 1; }  /* handle signal */
		else if (*s == '+') s++;
		if (isalnum((unsigned char)*s)) {
			lua_Number n = 0;
			do {
				int digit = (isdigit((unsigned char)*s)) ? *s - '0'
					: toupper((unsigned char)*s) - 'A' + 10;
				if (digit >= base) break;  /* invalid numeral; force a fail */
				n = n * (lua_Number)base + (lua_Number)digit;
				s++;
			} while (isalnum((unsigned char)*s));
			s += strspn(s, SPACECHARS);  /* skip trailing spaces */
			if (s == e) {  /* no invalid trailing characters? */
				lua_pushnumber(L, (neg) ? -n : n);
				return 1;
			}  /* else not a number */
		}  /* else not a number */
	}
	lua_pushnil(L);  /* not a number */
	return 1;
}


static int luaB_error (lua_State *L) {
	int level = luaL_optint(L, 2, 1);
	lua_settop(L, 1);
	if (lua_isstring(L, 1) && level > 0) {  /* add extra information? */
		luaL_where(L, level);
		lua_pushvalue(L, 1);
		lua_concat(L, 2);
	}
	return lua_error(L);
}


static int luaB_getmetatable (lua_State *L) {
	luaL_checkany(L, 1);
	if (!lua_getmetatable(L, 1)) {
		lua_pushnil(L);
		return 1;  /* no metatable */
	}
	luaL_getmetafield(L, 1, "__metatable");
	return 1;  /* returns either __metatable field (if present) or metatable */
}


static int luaB_setmetatable (lua_State *L) {
	int t = lua_type(L, 2);
	luaL_checktype(L, 1, LUA_TTABLE);
	luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
		"nil or table expected");
	if (luaL_getmetafield(L, 1, "__metatable"))
		return luaL_error(L, "cannot change a protected metatable");
	lua_settop(L, 2);
	lua_setmetatable(L, 1);
	return 1;
}


static int luaB_rawequal (lua_State *L) {
	luaL_checkany(L, 1);
	luaL_checkany(L, 2);
	lua_pushboolean(L, lua_rawequal(L, 1, 2));
	return 1;
}


static int luaB_rawlen (lua_State *L) {
	int t = lua_type(L, 1);
	luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
		"table or string expected");
	lua_pushinteger(L, lua_rawlen(L, 1));
	return 1;
}


static int luaB_rawget (lua_State *L) {
	luaL_checktype(L, 1, LUA_TTABLE);
	luaL_checkany(L, 2);
	lua_settop(L, 2);
	lua_rawget(L, 1);
	return 1;
}

static int luaB_rawset (lua_State *L) {
	luaL_checktype(L, 1, LUA_TTABLE);
	luaL_checkany(L, 2);
	luaL_checkany(L, 3);
	lua_settop(L, 3);
	lua_rawset(L, 1);
	return 1;
}


static int luaB_collectgarbage (lua_State *L) {
	static const char *const opts[] = {"stop", "restart", "collect",
		"count", "step", "setpause", "setstepmul",
		"setmajorinc", "isrunning", "generational", "incremental", NULL};
	static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
		LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
		LUA_GCSETMAJORINC, LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC};
	int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
	int ex = luaL_optint(L, 2, 0);
	int res = lua_gc(L, o, ex);
	switch (o) {
	case LUA_GCCOUNT: {
		int b = lua_gc(L, LUA_GCCOUNTB, 0);
		lua_pushnumber(L, res + ((lua_Number)b/1024));
		lua_pushinteger(L, b);
		return 2;
					  }
	case LUA_GCSTEP: case LUA_GCISRUNNING: {
		lua_pushboolean(L, res);
		return 1;
					 }
	default: {
		lua_pushinteger(L, res);
		return 1;
			 }
	}
}


static int luaB_type (lua_State *L) {
	luaL_checkany(L, 1);
	lua_pushstring(L, luaL_typename(L, 1));
	return 1;
}


static int pairsmeta (lua_State *L, const char *method, int iszero,
					  lua_CFunction iter) {
						  if (!luaL_getmetafield(L, 1, method)) {  /* no metamethod? */
							  luaL_checktype(L, 1, LUA_TTABLE);  /* argument must be a table */
							  lua_pushcfunction(L, iter);  /* will return generator, */
							  lua_pushvalue(L, 1);  /* state, */
							  if (iszero) lua_pushinteger(L, 0);  /* and initial value */
							  else lua_pushnil(L);
						  }
						  else {
							  lua_pushvalue(L, 1);  /* argument 'self' to metamethod */
							  lua_call(L, 1, 3);  /* get 3 values from metamethod */
						  }
						  return 3;
}


static int luaB_next (lua_State *L) {
	luaL_checktype(L, 1, LUA_TTABLE);
	lua_settop(L, 2);  /* create a 2nd argument if there isn't one */
	if (lua_next(L, 1))
		return 2;
	else {
		lua_pushnil(L);
		return 1;
	}
}


static int luaB_pairs (lua_State *L) {
	return pairsmeta(L, "__pairs", 0, luaB_next);
}


static int ipairsaux (lua_State *L) {
	int i = luaL_checkint(L, 2);
	luaL_checktype(L, 1, LUA_TTABLE);
	i++;  /* next value */
	lua_pushinteger(L, i);
	lua_rawgeti(L, 1, i);
	return (lua_isnil(L, -1)) ? 1 : 2;
}


static int luaB_ipairs (lua_State *L) {
	return pairsmeta(L, "__ipairs", 1, ipairsaux);
}


static int load_aux (lua_State *L, int status, int envidx) {
	if (status == LUA_OK) {
		if (envidx != 0) {  /* 'env' parameter? */
			lua_pushvalue(L, envidx);  /* environment for loaded function */
			if (!lua_setupvalue(L, -2, 1))  /* set it as 1st upvalue */
				lua_pop(L, 1);  /* remove 'env' if not used by previous call */
		}
		return 1;
	}
	else {  /* error (message is on top of the stack) */
		lua_pushnil(L);
		lua_insert(L, -2);  /* put before error message */
		return 2;  /* return nil plus error message */
	}
}


static int luaB_loadfile (lua_State *L) {
	const char *fname = luaL_optstring(L, 1, NULL);
	const char *mode = luaL_optstring(L, 2, NULL);
	int env = (!lua_isnone(L, 3) ? 3 : 0);  /* 'env' index or 0 if no 'env' */
	int status = luaL_loadfilex(L, fname, mode);
	return load_aux(L, status, env);
}


/*
** {======================================================
** Generic Read function
** =======================================================
*/


/*
** reserved slot, above all arguments, to hold a copy of the returned
** string to avoid it being collected while parsed. 'load' has four
** optional arguments (chunk, source name, mode, and environment).
*/
#define RESERVEDSLOT	5


/*
** Reader for generic `load' function: `lua_load' uses the
** stack for internal stuff, so the reader cannot change the
** stack top. Instead, it keeps its resulting string in a
** reserved slot inside the stack.
*/
static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
	(void)(ud);  /* not used */
	luaL_checkstack(L, 2, "too many nested functions");
	lua_pushvalue(L, 1);  /* get function */
	lua_call(L, 0, 1);  /* call it */
	if (lua_isnil(L, -1)) {
		lua_pop(L, 1);  /* pop result */
		*size = 0;
		return NULL;
	}
	else if (!lua_isstring(L, -1))
		luaL_error(L, "reader function must return a string");
	lua_replace(L, RESERVEDSLOT);  /* save string in reserved slot */
	return lua_tolstring(L, RESERVEDSLOT, size);
}


static int luaB_load (lua_State *L) {
	int status;
	size_t l;
	const char *s = lua_tolstring(L, 1, &l);
	const char *mode = luaL_optstring(L, 3, "bt");
	int env = (!lua_isnone(L, 4) ? 4 : 0);  /* 'env' index or 0 if no 'env' */
	if (s != NULL) {  /* loading a string? */
		const char *chunkname = luaL_optstring(L, 2, s);
		status = luaL_loadbufferx(L, s, l, chunkname, mode);
	}
	else {  /* loading from a reader function */
		const char *chunkname = luaL_optstring(L, 2, "=(load)");
		luaL_checktype(L, 1, LUA_TFUNCTION);
		lua_settop(L, RESERVEDSLOT);  /* create reserved slot */
		status = lua_load(L, generic_reader, NULL, chunkname, mode);
	}
	return load_aux(L, status, env);
}

/* }====================================================== */


static int dofilecont (lua_State *L) {
	return lua_gettop(L) - 1;
}


static int luaB_dofile (lua_State *L) {
	const char *fname = luaL_optstring(L, 1, NULL);
	lua_settop(L, 1);
	if (luaL_loadfile(L, fname) != LUA_OK)
		return lua_error(L);
	lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
	return dofilecont(L);
}


static int luaB_assert (lua_State *L) {
	if (!lua_toboolean(L, 1))
		return luaL_error(L, "%s", luaL_optstring(L, 2, "assertion failed!"));
	return lua_gettop(L);
}


static int luaB_select (lua_State *L) {
	int n = lua_gettop(L);
	if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
		lua_pushinteger(L, n-1);
		return 1;
	}
	else {
		int i = luaL_checkint(L, 1);
		if (i < 0) i = n + i;
		else if (i > n) i = n;
		luaL_argcheck(L, 1 <= i, 1, "index out of range");
		return n - i;
	}
}


static int finishpcall (lua_State *L, int status) {
	if (!lua_checkstack(L, 1)) {  /* no space for extra boolean? */
		lua_settop(L, 0);  /* create space for return values */
		lua_pushboolean(L, 0);
		lua_pushstring(L, "stack overflow");
		return 2;  /* return false, msg */
	}
	lua_pushboolean(L, status);  /* first result (status) */
	lua_replace(L, 1);  /* put first result in first slot */
	return lua_gettop(L);
}


static int pcallcont (lua_State *L) {
	int status = lua_getctx(L, NULL);
	return finishpcall(L, (status == LUA_YIELD));
}


static int luaB_pcall (lua_State *L) {
	int status;
	luaL_checkany(L, 1);
	lua_pushnil(L);
	lua_insert(L, 1);  /* create space for status result */
	status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, pcallcont);
	return finishpcall(L, (status == LUA_OK));
}


static int luaB_xpcall (lua_State *L) {
	int status;
	int n = lua_gettop(L);
	luaL_argcheck(L, n >= 2, 2, "value expected");
	lua_pushvalue(L, 1);  /* exchange function... */
	lua_copy(L, 2, 1);  /* ...and error handler */
	lua_replace(L, 2);
	status = lua_pcallk(L, n - 2, LUA_MULTRET, 1, 0, pcallcont);
	return finishpcall(L, (status == LUA_OK));
}


static int luaB_tostring (lua_State *L) {
	luaL_checkany(L, 1);
	luaL_tolstring(L, 1, NULL);
	return 1;
}


static const luaL_Reg base_funcs[] = {
	{"assert", luaB_assert},
	{"collectgarbage", luaB_collectgarbage},
	{"dofile", luaB_dofile},
	{"error", luaB_error},
	{"getmetatable", luaB_getmetatable},
	{"ipairs", luaB_ipairs},
	{"loadfile", luaB_loadfile},
	{"load", luaB_load},
#if defined(LUA_COMPAT_LOADSTRING)
	{"loadstring", luaB_load},
#endif
	{"next", luaB_next},
	{"pairs", luaB_pairs},
	{"pcall", luaB_pcall},
	{"print", luaB_print},
	{"rawequal", luaB_rawequal},
	{"rawlen", luaB_rawlen},
	{"rawget", luaB_rawget},
	{"rawset", luaB_rawset},
	{"select", luaB_select},
	{"setmetatable", luaB_setmetatable},
	{"tonumber", luaB_tonumber},
	{"tostring", luaB_tostring},
	{"type", luaB_type},
	{"xpcall", luaB_xpcall},
	{NULL, NULL}
};


LUAMOD_API int luaopen_base (lua_State *L) {
	/* set global _G */
	lua_pushglobaltable(L);
	lua_pushglobaltable(L);
	lua_setfield(L, -2, "_G");
	/* open lib into global table */
	luaL_setfuncs(L, base_funcs, 0);
	lua_pushliteral(L, LUA_VERSION);
	lua_setfield(L, -2, "_VERSION");  /* set global _VERSION */
	return 1;
}

